Signature | Description | Parameters |
---|---|---|
template<typename ... Ts> DataFrame get_data_by_loc(Index2D<long> range) const; |
It returns a DataFrame (including the index and data columns) containing the data from location begin to location end. This function supports Python-like negative indexing. That is why the range type is long. |
Ts: The list of types for all columns. A type should be specified only once. range: The begin and end iterators for data |
template<typename ... Ts> DataFrame< get_data_by_loc(const std::vector<long> &locations) const; |
It returns a DataFrame (including the index and data columns) containing the data from locations, specified in locations vector. This function supports Python-like negative indexing. That is why the locations vector type is long. NOTE: The negative indexing is relative to the "index" column, which may not be the size as all other column. The returned DataFrame is in the same order as locations parameter |
Ts: The list of types for all columns. A type should be specified only once. locations: List of indices into the index column to copy data |
template<typename ... Ts> DataFrameView<I> get_view_by_loc(Index2D<long> range); |
It behaves like get_data_by_loc(), but it returns a DataFrameView. A view is a DataFrame that is a reference to the original DataFrame. So if you modify anything in the view the original DataFrame will also be modified. NOTE: There are certain operations that you cannot do with a view. For example, you cannot add/delete columns, etc. NOTE: Views could not be const, becuase you can change original data through views. |
Ts: The list of types for all columns. A type should be specified only once. range: The begin and end iterators for data |
template<typename ... Ts> DataFramePtrView<I> get_view_by_loc(const std::vector<long> &locations); |
It behaves like get_data_by_loc(locations), but it returns a DataFramePtrView. A view is a DataFrame that is a reference to the original DataFrame. So if you modify anything in the view the original DataFrame will also be modified. NOTE: There are certain operations that you cannot do with a view. For example, you cannot add/delete columns, etc. NOTE: Views could not be const, becuase you can change original data through views. |
Ts: The list of types for all columns. A type should be specified only once. locations: List of indices into the index column to copy data |
template<typename ... Ts> DataFrameConstView<I> get_view_by_loc(Index2D<long> range) const; |
Same as above view, but it returns a const view. You can not change data in const views. But if the data is changed in the original DataFrame or through another view, it is refelcted in the const view. |
Ts: The list of types for all columns. A type should be specified only once. range: The begin and end iterators for data |
template<typename ... Ts> DataFrameConstPtrView<I> get_view_by_loc(const std::vector<long> &locations) const; |
Same as above view, but it returns a const view. You can not change data in const views. But if the data is changed in the original DataFrame or through another view, it is refelcted in the const view. |
Ts: The list of types for all columns. A type should be specified only once. locations: List of indices into the index column to copy data |
static void test_get_data_by_loc_slicing() { std::cout << "\nTesting get_data_by_loc()/slicing ..." << std::endl; std::vector<unsigned long> idx = { 123450, 123451, 123452, 123450, 123455, 123450, 123449 }; std::vector<double> d1 = { 1, 2, 3, 4, 5, 6, 7 }; std::vector<double> d2 = { 8, 9, 10, 11, 12, 13, 14 }; std::vector<double> d3 = { 15, 16, 17, 18, 19, 20, 21 }; std::vector<double> d4 = { 22, 23, 24, 25 }; MyDataFrame df; df.load_data(std::move(idx), std::make_pair("col_1", d1), std::make_pair("col_2", d2), std::make_pair("col_3", d3), std::make_pair("col_4", d4)); MyDataFrame df2 = df.get_data_by_loc<double>(Index2D<long> { 3, 6 }); MyDataFrame df3 = df.get_data_by_loc<double>(Index2D<long> { 0, 7 }); MyDataFrame df4 = df.get_data_by_loc<double>(Index2D<long> { -4, -1 }); MyDataFrame df5 = df.get_data_by_loc<double>(Index2D<long> { -4, 6 }); df.write<std::ostream, double>(std::cout); df2.write<std::ostream, double>(std::cout); df3.write<std::ostream, double>(std::cout); df4.write<std::ostream, double>(std::cout); df5.write<std::ostream, double>(std::cout); try { MyDataFrame df2 = df.get_data_by_loc<double>(Index2D<long> { 3, 8 }); } catch (const BadRange &ex) { std::cout << "Caught: " << ex.what() << std::endl; } try { MyDataFrame df2 = df.get_data_by_loc<double>(Index2D<long> { -8, -1 }); } catch (const BadRange &ex) { std::cout << "Caught: " << ex.what() << std::endl; } } // ----------------------------------------------------------------------------- static void test_get_view_by_loc() { std::cout << "\nTesting get_view_by_loc() ..." << std::endl; std::vector<unsigned long> idx = { 123450, 123451, 123452, 123450, 123455, 123450, 123449 }; std::vector<double> d1 = { 1, 2, 3, 4, 5, 6, 7 }; std::vector<double> d2 = { 8, 9, 10, 11, 12, 13, 14 }; std::vector<double> d3 = { 15, 16, 17, 18, 19, 20, 21 }; std::vector<double> d4 = { 22, 23, 24, 25 }; std::vector<std::string> s1 = { "11", "22", "33", "xx", "yy", "gg", "string" }; MyDataFrame df; df.load_data(std::move(idx), std::make_pair("col_1", d1), std::make_pair("col_2", d2), std::make_pair("col_3", d3), std::make_pair("col_4", d4), std::make_pair("col_str", s1)); auto memory_use1 = df.get_memory_usage<double>("col_3"); std::cout << "DataFrame Memory Usage:\n" << memory_use1 << std::endl; typedef DataFrameView<unsigned long> MyDataFrameView; typedef DataFrameConstView<unsigned long> MyDataFrameConstView; const MyDataFrame &const_df = df; MyDataFrameView dfv = df.get_view_by_loc<double, std::string>(Index2D<long> { 3, 6 }); MyDataFrameView dfv2 = df.get_view_by_loc<double, std::string>(Index2D<long> { -5, -1 }); MyDataFrameConstView dfcv = const_df.get_view_by_loc<double, std::string>(Index2D<long> { 3, 6 }); MyDataFrameConstView dfcv2 = const_df.get_view_by_loc<double, std::string>(Index2D<long> { -5, -1 }); dfv.shrink_to_fit<double, std::string>(); dfv.write<std::ostream, double, std::string>(std::cout); dfv2.write<std::ostream, double, std::string>(std::cout); dfv.get_column<double>("col_3")[0] = 88.0; assert(dfv.get_column<double>("col_3")[0] == df.get_column<double>("col_3")[3]); assert(dfv.get_column<double>("col_3")[0] == 88.0); assert(dfcv.get_column<double>("col_3")[0] == df.get_column<double>("col_3")[3]); assert(dfcv.get_column<double>("col_3")[0] == 88.0); auto memory_use2 = dfv.get_memory_usage<double>("col_3"); std::cout << "View Memory Usage:\n" << memory_use2 << std::endl; } // ----------------------------------------------------------------------------- static void test_get_data_by_loc_location() { std::cout << "\nTesting get_data_by_loc(locations) ..." << std::endl; std::vector<unsigned long> idx = { 123450, 123451, 123452, 123450, 123455, 123450, 123449 }; std::vector<double> d1 = { 1, 2, 3, 4, 5, 6, 7 }; std::vector<double> d2 = { 8, 9, 10, 11, 12, 13, 14 }; std::vector<double> d3 = { 15, 16, 17, 18, 19, 20, 21 }; std::vector<double> d4 = { 22, 23, 24, 25 }; MyDataFrame df; df.load_data(std::move(idx), std::make_pair("col_1", d1), std::make_pair("col_2", d2), std::make_pair("col_3", d3), std::make_pair("col_4", d4)); MyDataFrame df2 = df.get_data_by_loc<double>(std::vector<long> { 3, 6 }); MyDataFrame df3 = df.get_data_by_loc<double>(std::vector<long> { -4, -1 , 5 }); assert(df2.get_index().size() == 2); assert(df2.get_column<double>("col_3").size() == 2); assert(df2.get_column<double>("col_2").size() == 2); assert(df2.get_index()[0] == 123450); assert(df2.get_index()[1] == 123449); assert(df2.get_column<double>("col_3")[0] == 18.0); assert(df2.get_column<double>("col_2")[1] == 14.0); assert(std::isnan(df2.get_column<double>("col_4")[1])); assert(df3.get_index().size() == 3); assert(df3.get_column<double>("col_3").size() == 3); assert(df3.get_column<double>("col_2").size() == 3); assert(df3.get_column<double>("col_1").size() == 3); assert(df3.get_index()[0] == 123450); assert(df3.get_index()[1] == 123449); assert(df3.get_index()[2] == 123450); assert(df3.get_column<double>("col_1")[0] == 4.0); assert(df3.get_column<double>("col_2")[2] == 13.0); assert(df3.get_column<double>("col_4")[0] == 25.0); assert(std::isnan(df3.get_column<double>("col_4")[1])); assert(std::isnan(df3.get_column<double>("col_4")[2])); } // ----------------------------------------------------------------------------- static void test_get_view_by_loc_location() { std::cout << "\nTesting get_view_by_loc(locations) ..." << std::endl; std::vector<unsigned long> idx = { 123450, 123451, 123452, 123450, 123455, 123450, 123449 }; std::vector<double> d1 = { 1, 2, 3, 4, 5, 6, 7 }; std::vector<double> d2 = { 8, 9, 10, 11, 12, 13, 14 }; std::vector<double> d3 = { 15, 16, 17, 18, 19, 20, 21 }; std::vector<double> d4 = { 22, 23, 24, 25 }; MyDataFrame df; df.load_data(std::move(idx), std::make_pair("col_1", d1), std::make_pair("col_2", d2), std::make_pair("col_3", d3), std::make_pair("col_4", d4)); const MyDataFrame &const_df = df; auto dfv1 = df.get_view_by_loc<double>(std::vector<long> { 3, 6 }); auto dfv2 = df.get_view_by_loc<double>(std::vector<long> { -4, -1 , 5 }); auto const_dfv1 = const_df.get_view_by_loc<double>(std::vector<long> { 3, 6 }); auto const_dfv2 = const_df.get_view_by_loc<double>(std::vector<long> { -4, -1 , 5 }); assert(dfv1.get_index().size() == 2); assert(dfv1.get_column<double>("col_3").size() == 2); assert(dfv1.get_column<double>("col_2").size() == 2); assert(dfv1.get_index()[0] == 123450); assert(dfv1.get_index()[1] == 123449); assert(dfv1.get_column<double>("col_3")[0] == 18.0); assert(dfv1.get_column<double>("col_2")[1] == 14.0); assert(std::isnan(dfv1.get_column<double>("col_4")[1])); assert(const_dfv1.get_index().size() == 2); assert(const_dfv1.get_column<double>("col_3").size() == 2); assert(const_dfv1.get_column<double>("col_2").size() == 2); assert(const_dfv1.get_index()[0] == 123450); assert(const_dfv1.get_index()[1] == 123449); assert(const_dfv1.get_column<double>("col_3")[0] == 18.0); assert(const_dfv1.get_column<double>("col_2")[1] == 14.0); assert(std::isnan(const_dfv1.get_column<double>("col_4")[1])); assert(dfv2.get_index().size() == 3); assert(dfv2.get_column<double>("col_3").size() == 3); assert(dfv2.get_column<double>("col_2").size() == 3); assert(dfv2.get_column<double>("col_1").size() == 3); assert(dfv2.get_index()[0] == 123450); assert(dfv2.get_index()[1] == 123449); assert(dfv2.get_index()[2] == 123450); assert(dfv2.get_column<double>("col_1")[0] == 4.0); assert(dfv2.get_column<double>("col_2")[2] == 13.0); assert(dfv2.get_column<double>("col_4")[0] == 25.0); assert(std::isnan(dfv2.get_column<double>("col_4")[1])); assert(std::isnan(dfv2.get_column<double>("col_4")[2])); assert(const_dfv2.get_index().size() == 3); assert(const_dfv2.get_column<double>("col_3").size() == 3); assert(const_dfv2.get_column<double>("col_2").size() == 3); assert(const_dfv2.get_column<double>("col_1").size() == 3); assert(const_dfv2.get_index()[0] == 123450); assert(const_dfv2.get_index()[1] == 123449); assert(const_dfv2.get_index()[2] == 123450); assert(const_dfv2.get_column<double>("col_1")[0] == 4.0); assert(const_dfv2.get_column<double>("col_2")[2] == 13.0); assert(const_dfv2.get_column<double>("col_4")[0] == 25.0); assert(std::isnan(const_dfv2.get_column<double>("col_4")[1])); assert(std::isnan(const_dfv2.get_column<double>("col_4")[2])); dfv2.get_column<double>("col_1")[0] = 101.0; assert(dfv2.get_column<double>("col_1")[0] == 101.0); assert(const_dfv2.get_column<double>("col_1")[0] == 101.0); assert(df.get_column<double>("col_1")[3] == 101.0); auto memory_use = dfv2.get_memory_usage<double>("col_3"); std::cout << "View Memory Usage:\n" << memory_use << std::endl; }